South African Class 7E1

South African Class 7E1
E7111 at Vryheid, KwaZulu-Natal, 16 August 2007
Power type Electric
Designer Hitachi
Builder Hitachi
Dorbyl
Model Hitachi 7E1
Build date 1979-1981
Total produced 50
UIC classification Co-Co
Gauge 3 ft 6 in (1,067 mm) Cape gauge
Bogies 4.4 m (14 ft 5.2 in) wheelbase
Wheel diameter 1,220 mm (48.0 in)
Wheelbase 13.8 m (45 ft 3.3 in)
Length 18.43 m (60 ft 5.6 in)
Width 2.906 m (9 ft 6.4 in)
Height 4.18 m (13 ft 8.6 in) pantographs down
Axle load 21,000 kg (20.7 long tons)
Locomotive weight 125,500 kg (123.5 long tons)
Current collection
method		 Pantographs
Traction motors Six HS 1054 GR
Transmission 16/94 Gear ratio
Top speed 100 km/h (62 mph)
Power output Per motor:
515 kW (691 hp) 1 hour
500 kW (670 hp) continuous
Total:
3,150 kW (4,220 hp) 1 hour
3,000 kW (4,000 hp) continuous
Tractive effort 450 kN (100,000 lbf) starting
319 kN (72,000 lbf) 1 hour
300 kN (67,000 lbf) continuous
Locomotive brakes Rheostatic[1]
Train brakes Air & Vacuum
Career South African Railways
Spoornet
Transnet Freight Rail
Class Class 7E1[2]
Power class 25 kV AC
Number in class 50
Number E7101-E7150
Delivered 1980-1981
First run 1980

Between 1980 and 1981 the South African Railways placed fifty Class 7E1 electric locomotives with a Co-Co wheel arrangement in main line service.[2]

Contents

Manufacturers

The Class 7E1 25 kV AC electric locomotive was designed for the South African Railways (SAR) by Hitachi, while Dorbyl in South Africa supplied the mechanical components. The first two locomotives, numbered E7101 and E7102, were built by Hitachi in Japan in 1979, while forty-eight more were built by Dorbyl in South Africa between 1979 and 1981 and numbered E7103 to E7150.[1][3]

Like Union Carriage and Wagon, neither Hitachi nor Dorbyl allocated builder’s numbers to the Class 7E1 locomotives it built for the SAR. While usual practice by most other locomotive builders was to allocate builder’s numbers or works numbers to record the locomotives built by them, Hitachi and Dorbyl apparently also used the SAR running numbers for their record keeping.[2]

Features

Since they were acquired solely for use on the Richards Bay coal line where they would always work in multiple, they were built with single cabs. Following the Class 9E that entered service in 1978, the Class 7E1 was the second single cab main line electric locomotive to be acquired by the SAR. Until the Class 9E was introduced, all South African main line electric locomotives were dual cab units.[2]

The two sides of the Class 7E1 are sufficiently different in appearance that, when coupled end to end, a pair of them appears at first glance to be two different locomotive types. The left side is smooth, while the right has several large grilles.[2]

On the Class 7E1 control of traction and rheostatic braking is by stepless solid-state electronics. The electrical equipment was designed for high power factor operation, obtained by the switching in of power-factor correction capacitors.[1]

Service

The Class 7E1 was placed in service on the 25 kV AC Ermelo-Richards Bay Coalink line, where they still work. In the period from the early 1990s until about 2007 various modifications to improve downhill braking capacity were done to the Coalink line Hitachi designed locomotives. The first set of upgrades were done on the fifty Class 7E1 locomotives. They retained their Class 7E1 classification after modification.[1][3]

Liveries

The main picture shows E7111’s right side, in SAR Gulf Red and whiskers livery.

See also

References

  1. ^ a b c d Paxton, Leith; Bourne, David (1985). Locomotives of the South African Railways (1st ed.). Cape Town: Struik. pp. 129-131. ISBN 0869772112. 
  2. ^ a b c d e South African Railways Index and Diagrams Electric and Diesel Locomotives, 610mm and 1065mm Gauges, Ref LXD 14/1/100/20, 28 January 1975, as amended
  3. ^ a b Middleton, John N. (2002). Railways of Southern Africa Locomotive Guide - 2002 (as amended by Combined Amendment List 4, January 2009) (2nd, Dec 2002 ed.). Herts, England: Beyer-Garratt Publications. pp. 51, 61.